Here is a really great article from Alley Cat Allies. If you are in the Toronto area and see a cat wandering your neighbourhood, please check www.helpinglostpets.com to see if it is someone's lost cat. Do not assume that this cat has been abandoned or is feral.
You can also ask for assistance from your local rescues as to which rescues can assist you to see that the cat is taken care of either as a feral (fixed, vaccinated and colony caretaker) or stray (getting vetting and a home).
You can contact Community Cats (Toronto Feral Cat Coalition) to find out if there is a colony caretaker in your area.
Please don't ignore these cats in need.